This invention relates generally to fuze devices which render a fuze safe to handle, and more particularly to a circuit for preventing detonation of an explosive after a predetermined period of time has lapsed, such as a thirty minute time period. In a preferred embodiment, the circuit comprises a fuze Explosive Ordnance Disposal (EOD) circuit.
The use of explosive weapons and fuzes are known in the art. On occasion, explosive devices fail to detonate at the appropriate time. Such munitions are referred to as duds, and are often very dangerous because the device may remain armed and therefore capable of high order detonation for an indefinite period of time. Duds typically present a danger to friendly personnel subsequently operating in the field, battlefield cleanup crews and even civilians long after a time of conflict.
When an explosive device has failed to detonate within a predetermined mission time, or the period of time within which proper detonation can be expected, it is desirable to render the fuze safe to prevent subsequent detonation.
Prior art methods of accomplishing sterilization of a fuze have typically used mechanical means of interrupting the battery power. For example, the M762/M767 fuzes utilize a mechanical spin switch that closes the battery circuit only while the fuze is experiencing a spin force.
Mechanical devices can have limited reliability and higher failure rates when compared to electronic devices that perform similar functions. Interacting mechanical components can wear, corrode and even seize over time. Devices with moving parts may also have difficulty withstanding the high shock levels associated with the normal operating environment of explosives devices, particularly with respect to artillery and other projectile weapons.
Some fuzes with electrically initiated explosive trains, such as the XM773 fuze, simply use a resistor to dissipate the firing energy and any remaining battery energy to below a safe voltage or energy level.
However, for many present fuzes, which are designed to be used in a variety of applications, a simple resistor dissipation circuit is not practical. Multi-option fuzes, such as the M782 MOFA fuze, have multiple operating modes and are designed to satisfy a wide range of current requirements. As such, a resistor dissipation circuit is not always sufficient to reliably dissipate the energy from both the firing capacitor and the battery within the desired time frame, which is often thirty minutes.
Therefore, it would be desirable to provide a device for electronically preventing detonation of an explosive that failed to properly detonate within a predetermined mission time. Desirably, the device will reliably function with all operating modes and for all applications of a multi-option fuze. Further, it would be desirable to produce such a device using common components that are available at a relatively low cost.
Without limiting the scope of the invention a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.
A brief abstract of the technical disclosure in the specification is provided as well only for the purposes of complying with 37 C.F.R. 1.72. The abstract is not intended to be used for interpreting the scope of the claims.
All US patents and applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.